Surgeon-performed ultrasonography as an adjunct to minimally invasive radio-guided parathyroidectomy in 100 consecutive patients with primary hyperparathyroidism.

OBJECTIVE: To examine whether surgeon-performed ultrasonography (SPU) in patients with primary hyperparathyroidism and negative preoperative sestamibi scans improves adenoma localization, increases the directed unilateral exploration rate, and reduces operative time and length of hospital stay. METHODS: We retrospectively analyzed 100 consecutive patients with primary hyperparathyroidism encountered between January 1, 2005, and March 31, 2007. Patients underwent preoperative sestamibi scanning and SPU. Minimally invasive radio-guided parathyroidectomy (MIRP) was performed on patients with positive sestamibi scans. In sestamibi scan-negative patients, unilateral exploration was performed with removal of the adenoma, which was submitted for frozen section. Accuracy, operative time, hospital length of stay, mortality, and morbidity were assessed. RESULTS: Of 100 patients, 79 had positive sestamibi scans and underwent MIRP. Twenty-one had negative sestamibi scans, 18 of whom underwent SPU. Parathyroid adenoma was localized in 17 (94%) of the 18 patients. Operative time and length of hospital stay were not significantly different between sestamibi scan-negative patients who underwent SPU with directed unilateral exploration and sestamibi scan-positive patients who underwent MIRP (operative time: 46 minutes vs 38 minutes, respectively; length of hospital stay: 17.8 hours vs 16.1 hours, respectively). Operative time and length of hospital stay were significantly shorter in sestamibi scan-negative patients who underwent SPU with directed unilateral exploration and in patients who underwent MIRP than in historical controls who underwent 4-gland exploration (P<.01 for both outcomes). No morbidity or mortality was documented. CONCLUSION: SPU localizes 94% of adenomas in sestamibi scan-negative patients, which allows for directed unilateral exploration and results in operative time and length of hospital stay not significantly different from patients undergoing MIRP.

BK polyomavirus in renal transplants: role of electron microscopy and immunostaining in detecting early infection.

Reactivation of BK polyomavirus (BKV) is increasingly recognized as a cause of failure of renal allografts. Since no specific treatment is available for this infection, early diagnosis is important, as it allows for early intervention and possible recovery of renal function. Forty-four consecutive renal transplant biopsies performed over a 2-year period were included in the study. In addition to evaluation of renal biopsy tissue sections using routine histochemical stains, CD3, CD20, BK virus immunostains using the specific BK virus and the SV40 antibodies and electron microscopy studies were performed. None of the transplant cases but one exhibited classical histologic viral changes. Viral particles were seen by EM in 19%, and BK-virus positivity was identified in only 43% of these cases. CD20-rich inflammatory infiltrates predominated in cases in which either positive BK stain and/or viral particles were identified ultrastructurally. A combined approach using electron microscopic and immunohistochemical evaluation can be utilized effectively to identify BK virus-associated nephropathy at an early phase facilitating early clinical intervention.

Minimally invasive radio-guided parathyroidectomy in 152 consecutive patients with primary hyperparathyroidism.

OBJECTIVE: To examine the results of minimally invasive radio-guided parathyroidectomy (MIRP) in the treatment of patients with primary hyperparathyroidism, including factors associated with negative technetium-labeled sestamibi scanning. METHODS: We retrospectively analyzed the findings in a group of 152 consecutive patients encountered during the period 2001 through 2004. The overall accuracy of preoperative sestamibi scanning was assessed, and the success of MIRP was determined on the basis of operative time, duration of hospital stay, and rate of complications. RESULTS: All 152 patients underwent preoperative sestamibi scanning; 118 (78%) had positive scans and were treated with MIRP, whereas 34 (22%) had negative scans and underwent traditional neck explorations. Patients with negative sestamibi scans had 5 times the incidence of concomitant thyroid disease in comparison with those who had positive sestamibi scans (P<0.01), and they had higher rates of parathyroid hyperplasia (26% versus 0%; P<0.01). In comparison with traditional neck dissection, MIRP-treated patients had shorter operative times (38 minutes versus 86 minutes; P<0.01) and shorter hospital stays (0.67 day versus 1.09 days; P<0.01). Among the MIRP-treated patients, 67% were discharged the same day as performance of the outpatient surgical procedure. Correction of hypercalcemia was accomplished in 116 of 118 patients (98%) who underwent MIRP. Complications in the MIRP group were low, including 1 postoperative hemorrhage. No cases of recurrent laryngeal nerve injury occurred. There were 2 false-positive sestamibi scans (1.3%). CONCLUSION: Parathyroid hyperplasia and concomitant thyroid pathologic conditions are associated with negative preoperative sestamibi scans. MIRP is applicable in 78% of patients with primary hyperparathyroidism and is a safe, effective operation that results in shorter surgical time, reduced hospital stay, and minimal complications.

Cyclooxygenase-2 expression in brain metastases.

BACKGROUND: Elevated Cyclooxygenase-2 (COX-2) expression is thought to increase metastatic potential of many tumors. Furthermore, elevated COX-2 expression correlates with radiation resistance in many tumor types. We evaluated whether: (i) the degree of COX-2 expression correlated with either metastatic tumor type or with the presence of necrosis and whether (ii) radiation-resistant tumors (renal cell and melanoma) had higher expression of COX-2 than did relatively radiation-sensitive tumors (breast and lung). MATERIALS AND METHODS: Specimens from sixteen patients who underwent resection of brain metastases were analyzed for COX-2 expression using a COX-2 antibody-based immunoassay. Specimens consisted of brain metastases from lung tumors, breast adenocarcinomas, melanomas and renal cell carcinomas. All specimens were analyzed for the presence or absence of necrosis. RESULTS: Ten of sixteen brain metastasis specimens had ten percent or less Cox-2 immunostaining. Statistical analyses showed no correlation between Cox-2 immunostaining and metastatic tumor type or between Cox-2 immunostaining and necrosis in this study. Furthermore, renal cell carcinoma and melanoma showed variable Cox-2 immunostaining. CONCLUSION: Cox-2 is not consistently expressed in metastases to the brain. The degree of Cox-2 expression does not correlate with metastatic tumor type or with the presence of necrosis. Radioresistant tumors did not have statistically different expression of Cox-2 than radiosensitive specimens studied in this analysis.

Expression of eukaryotic initiation factor 4E in astrocytic tumors.

Upregulation of expression of the eukaryotic initiation factor 4E (eIF4E) has been identified in breast carcinomas, squamous cell carcinomas in the head and neck regions, and transitional cell carcinomas of urinary bladder. In this immunohistochemical study, eIF4E protein expression was investigated in human brain tissue from patients without central nervous system diseases and brain biopsy tissues from patients with anaplastic astrocytoma and glioblastoma multiforme. Expression of eIF4E protein was observed in normal pyramidal neurons but not in neuroglial components. In anaplastic astrocytoma and glioblastoma multiforme, there was diffuse uniform expression of eIF4E immunoreactivity in malignant astrocytes. A similar pattern of immunoreactivity was also present in proliferative endothelial cells and vascular lining endothelial cells in glioblastoma multiforme. This study provides evidence that eIF4E is upregulated in high-grade astrocytic tumors. As in other malignancies, a high level of eIF4E may play an important role in the neoplastic transformation, angiogenesis, and tumor growth in astrocytic tumors. Because eIF4E is crucial in regulation of tumor growth, eIF4E could be a potential target for inhibitors as an adjuvant therapy for brain tumors.

Intestinal and oncocytic variants of pancreatic intraepithelial neoplasia. A morphological and immunohistochemical study.

We report 2 previously undescribed morphological variants of pancreatic intraepithelial neoplasia (PanIN). The first variant with an intestinal phenotype was associated with mucinous carcinomas that occurred in the tail of the pancreas of 2 men (60 and 65 years old). The carcinomas lacked the characteristic ovarian-like stroma of mucinous cystic neoplasms observed in female patients and did not show a papillary architecture. Whether they represent mucinous cystadenocarcinomas or mucinous carcinomas that arose from the flat variant of intraductal papillary mucinous neoplasms could not be determined with certainty. Microscopically, the intestinal type of PanIN was composed of pseudostratified columnar cells similar to those of colonic adenomas and showing variable degrees of dysplasia. A significant increase in the MIB-1 labeling index correlated with the severity of dysplasia. In contrast to conventional PanIN, the intestinal variant expressed MUC-2 and was MUC-1 negative. The second type of PanIN had an oncocytic phenotype, coexpressed MUC-2 and MUC-1 mucins, and was associated with intraductal oncocytic papillary carcinomas that showed a similar immunohistochemical mucin profile. Both intestinal and oncocytic types of PanIN expressed DPC4 and lacked p53 reactivity. The anatomical separation of the PanINs from the carcinomas and the gradual progression of cytological and architectural abnormalities in both variants of PanIN argue against ductal spread (cancerization of the ducts). The intestinal and oncocytic variants of PanIN broaden the morphological spectrum of this intraductal lesion. Although their significance is unknown, the possibility that these PanIN variants represent cancer precursors should be considered.